EP3585840B1 - Silicone compositions that can be cross-linked by irradiation with uv light - Google Patents

Description

Addition-crosslinking silicone rubbers can be vulcanized in various ways. Above all, thermally induced crosslinking is common. However, light-induced, in particular UV-induced, crosslinking is also used.

Addition-crosslinking silicone compositions can be formulated as one-component or two-component systems. One-component systems have the great advantage for users that there is no need to mix two or more components. However, in order to be able to supply a thermally crosslinking system as a component, a very high storage stability, ie long curing time at room temperature ("pot life") and / or z. T. also shipping and storage under cooling necessary. Such a long pot life, e.g. B. of more than 6 months, can only be achieved by using special platinum catalysts or a large amount of vulcanization retarders, so-called inhibitors. However, inhibitors have the disadvantage that they impair the crosslinking rate.

The use of special platinum catalysts with phosphites as ligands in silicone compositions thermally crosslinkable by hydrosilylation is over US 2009/0088524 A1 known. The pot lives are improved compared to conventional platinum catalysts, such as the platinum-divinyltetramethylsiloxane complex (so-called Karstedt catalyst). However, the light-off temperatures at which crosslinking begins also increase.

In I. Kownacki et al., Applied Catalysis A: General 362 (2009) 106-114 are used in the thermal crosslinking of silicones Hydrosilylation Triorganophosphites used as inhibitors of platinum catalysts, such as the Karstedt catalyst, with which a sufficiently long pot life is achieved. However, it is also pointed out that the use of these phosphites can lead to an increase in crosslinking times.

Very high temperatures of more than 100 ° C. are therefore generally required for curing one-component thermally crosslinkable silicone compositions or those with a very long pot life, or alternatively very long curing times have to be accepted when using lower temperatures. For crosslinking at the usually high temperatures, heat must be transferred to the rubber by tempering furnaces. Not only is this very energy-intensive, it is often simply not possible. Some materials with which the silicone compositions have to be brought into contact melt, change or decompose at these temperatures. Especially in the fields of the electrical industry, electronics industry and medical technology, silicon compounds with these materials are of great importance.

Compared to thermal crosslinking, UV-induced crosslinking has the advantage that only UV light is required as an energy source and curing can take place very quickly after irradiation. The suitability of cyclopentadienyl complexes of platinum for UV-activated hydrosilylation is, for example, out US 4,600,484 , US 8,088,878 B2 and WO 2016/030325 A1 known. However, instabilities can also occur with UV-crosslinking silicone rubber compounds, which impair storage stability. The gelling time of two-component compositions often becomes shorter and shorter during storage, even when stored in the dark, i.e. they begin to gel faster and faster as storage progresses, while one-component compositions begin to vulcanize.

In WO 2010/009752 A1 Thermally crosslinking silicone compositions are described which contain phosphites with aliphatic polycyclic radicals.

It was therefore an object to avoid the disadvantages mentioned above and to provide silicone compositions which have a good shelf life, even as one-component systems, enable rapid curing when irradiated, the crosslinking rate remaining essentially unaffected and curing taking place at room temperature, i.e. with low energy Avoiding high temperatures is possible. The object is achieved by the invention.

1. (A) Organosiliciumverbindungen, die Si-C-gebundene Reste mit aliphatischen Kohlenstoff-Kohlenstoff-Mehrfachbindungen aufweisen,
2. (B) Organosiliciumverbindungen mit Si-gebundenen Wasserstoffatomen
   oder anstelle von (A) und (B)
3. (C) Organosiliciumverbindungen, die Si-C-gebundene Reste mit aliphatischen Kohlenstoff-Kohlenstoff-Mehrfachbindungen und Si-gebundene Wasserstoffatome aufweisen,
4. (D) durch Licht der Wellenlänge von 200 bis 500 nm, vorzugsweise UV-Licht der Wellenlänge 200 bis 400 nm, aktivierbare Platinkatalysatoren ausgewählt aus der Gruppe der Cyclopentadienyl-Komplexe des Platins und
5. (E) phosphororganische Verbindungen ausgewählt aus der Gruppe der Formeln
   
           P(=O)_u[(OR¹⁰)]_s[R¹¹]_t     (I),
   
           P[(O)_iSiR¹² ₃]₃     (II),
   
   
   
   und deren Mischungen,
   • wobei R¹⁰ und R¹¹ gleich oder verschieden sind und jeweils einen Alkylrest der Formel C_jH_2j+1 mit j=2-31 oder einen Alkenylrest der Formel C_kH_2k-1 mit k=2-31 oder einen Aryl- oder Alkylarylrest der Formel - (C₆H_5-w) - (C_vH_2v+1)_w mit v = 1-18 und w = 0-5 bedeuten,
   • R¹² gleich oder verschieden ist und einen einwertigen Kohlenwasserstoffrest mit 1 bis 18 C-Atomen bedeutet,
   • R¹³ ein vierwertiger Kohlenwasserstoffrest mit 5 bis 30 C-Atomen bedeutet,
   • R¹⁴ gleich oder verschieden ist und die Bedeutung von R¹⁰ hat,
   • s 0, 1, 2 oder 3 ist,
   • t 0, 1, 2 oder 3 ist,
   • mit der Maßgabe, dass die Summe s+t gleich 3 ist,
   • u 0 oder 1, bevorzugt 0, ist und
   • i 0 oder 1, bevorzugt 1, ist.

The invention relates to irradiation with light, preferably UV light, containing crosslinkable silicone compositions

1. (A) organosilicon compounds which have Si-C-bonded radicals with aliphatic carbon-carbon multiple bonds,
2. (B) Organosilicon compounds with Si-bonded hydrogen atoms
   or instead of (A) and (B)
3. (C) organosilicon compounds which have Si-C-bonded radicals with aliphatic carbon-carbon multiple bonds and Si-bonded hydrogen atoms,
4. (D) platinum catalysts which can be activated by light of the wavelength from 200 to 500 nm, preferably UV light of the wavelength 200 to 400 nm, selected from the group of the cyclopentadienyl complexes of platinum and
5. (E) organophosphorus compounds selected from the group of the formulas
   
   P (= O) _u [(OR ¹⁰ )] _s [R ¹¹ ] _t (I),
   
   P [(O) _i SiR ¹² ₃ ] ₃ (II),
   
   
   
   and their mixtures,
   • wherein R ¹⁰ and R ^{11 are the} same or different and each an alkyl radical of the formula C _j H _{2j + 1} with j = 2-31 or an alkenyl radical of the formula C _k H _2k-1 with k = 2-31 or an aryl or Alkylaryl radical of the formula - (C ₆ H _5-w ) - (C _v H _{2v + 1} ) _w with v = 1-18 and w = 0-5,
   • R ^{12 is the} same or different and denotes a monovalent hydrocarbon radical having 1 to 18 carbon atoms,
   • R ¹³ denotes a tetravalent hydrocarbon radical with 5 to 30 carbon atoms,
   • R ^{14 is the} same or different and has the meaning of R ¹⁰ ,
   • s is 0, 1, 2 or 3,
   • t is 0, 1, 2 or 3,
   • with the proviso that the sum s + t is 3,
   • u is 0 or 1, preferably 0, and
   • i is 0 or 1, preferably 1.

Examples of radicals R ¹⁰ are the ethyl, propyl, phenyl, nonylphenyl, dinonylphenyl, 2-ethylhexyl, 2,4-di-tert-butylphenyl radical and 2-tert-butyl-4-methylphenyl radical.

Examples of R ¹¹ radicals are the phenyl radical.

R ¹² hydrocarbon radicals in formula (II) are preferably alkyl, alkenyl, aryl or alkaryl radicals.
Examples of radicals R ¹² are the methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl and hexyl radical, the methyl and tert-butyl radical being preferred.

A preferred example of R ¹³ in formula (III) is the following radical of formula C (CH ₂ -) ₄ :

Examples of radicals R ¹⁴ in formula (III) are the octadecyl, 2,4-di-tert-butylphenyl and 2,6-di-tert-butyl-4-methylphenyl radical.

Organophosphorus compounds of the formula (I) are preferably those of the formula with u = 0 and s = 3 and t = 0 as

P [(OR ¹⁰ )] ₃ (Ia)

or those of the formula with u = 0 and t = 3 and s = 0 as

P [R ¹¹ ] ₃ (Ib).

• Triethylphosphit
• Triphenylphosphit
• Tris(2,4-di-tert-butylphenyl)phosphit
• Tris(2-tert-butyl-4-methylphenyl)phosphit
• Tris(1-adamantanemethyl)phosphit
• Triisopropylphosphit
• Triisodecylphosphit
• Tris(2-ethylhexyl)phosphit
• Tris(nonylphenyl)phosphit
• Tris[(2-phenyl)phenyl]phosphit
• Tris[(3-phenyl)phenyl]phosphit
• Tris[(4-phenyl)phenyl]phosphit
• Tris[(5-phenyl)phenyl]phosphit
• Tris[(6-phenyl)phenyl]phosphit
• Tris[(2,4-diphenyl)phenyl]phosphit
• Tris[(2,6-diphenyl)phenyl]phosphit
• Tris[(3,5-diphenyl)phenyl]phosphit
• Tris(2,6-diisopropylphenyl)phosphit
• Tris(2-methylphenyl)phosphit
• Tris(2,4-dioctylphenyl)phosphit
• Tri(o-tolyl)phosphit
• Tricyclohexylphosphit
• Trilaurylphosphit
• Diisodecylphenylphosphit
• 2-Ethylhexyldiphenylphosphit
• Benzyldiphenylphosphin
• tert-Butyldiphenylphosphin
• Cyclohexyldiphenylphosphin
• Tri-n-butylphosphin
• Tri-tertbutyl-phosphin
• Tri-o-tolyl-phosphin
• Tri(p-tolyl)phosphin
• Tricylohexylphosphin
• Dimethylphenylphosphin

Examples of organophosphorus compounds of the formulas (Ia) and (Ib) are

• Triethyl phosphite
• Triphenyl phosphite
• Tris (2,4-di-tert-butylphenyl) phosphite
• Tris (2-tert-butyl-4-methylphenyl) phosphite
• Tris (1-adamantanemethyl) phosphite
• Triisopropyl phosphite
• Triisodecyl phosphite
• Tris (2-ethylhexyl) phosphite
• Tris (nonylphenyl) phosphite
• Tris [(2-phenyl) phenyl] phosphite
• Tris [(3-phenyl) phenyl] phosphite
• Tris [(4-phenyl) phenyl] phosphite
• Tris [(5-phenyl) phenyl] phosphite
• Tris [(6-phenyl) phenyl] phosphite
• Tris [(2,4-diphenyl) phenyl] phosphite
• Tris [(2,6-diphenyl) phenyl] phosphite
• Tris [(3,5-diphenyl) phenyl] phosphite
• Tris (2,6-diisopropylphenyl) phosphite
• Tris (2-methylphenyl) phosphite
• Tris (2,4-dioctylphenyl) phosphite
• Tri (o-tolyl) phosphite
• Tricyclohexyl phosphite
• Trilauryl phosphite
• Diisodecylphenyl phosphite
• 2-ethylhexyl diphenyl phosphite
• Benzyldiphenylphosphine
• tert-butyldiphenylphosphine
• Cyclohexyldiphenylphosphine
• Tri-n-butylphosphine
• Tri-tertbutyl phosphine
• Tri-o-tolyl-phosphine
• Tri (p-tolyl) phosphine
• Tricylohexylphosphine
• Dimethylphenylphosphine

Organophosphorus compounds of the formula (I) with u = 0 can also be those in which s is 1, 2 or 3 and t is 1, 2 or 3, with the proviso that the sum is s + t = 3.

• Tris(tert-butyldimethylsilyl)phosphit
• Tris(trimethylsilyl)phosphit bzw.
• Tris(trimethylsilyl)phosphine.

Examples of organophosphorus compounds of the formula (II) with i = 1 and i = 0 are

• Tris (tert-butyldimethylsilyl) phosphite
• Tris (trimethylsilyl) phosphite or
• Tris (trimethylsilyl) phosphine.

[3,9-Bis(octa-decyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecan].An example of the organophosphorus compound of the formula (III) is

[3,9-bis (octa-decyloxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane].

• (3,9-Bis(2,4-ditert-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane)
• Distearylpentaerythritdiphosphit
• Bis(2,6-di-tertbutyl-4-methylphenyl)-pentaerythritdiphosphit

Other examples are

• (3,9-bis (2,4-di-tert-butylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane)
• Distearylpentaerythritol diphosphite
• Bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite

The preparation of the organophosphorus compounds according to the invention is known, for example in I. Kownacki et al., Applied Catalysis A: General 362 (2009) 106-114 ;
US 4,692,540 A ; Y. Li et al., J. Am. Chem. Soc. 134 (2012) 18325-18329 ; GB 944 062 A ; US 6,653,494 B2 ; EP 2 239 248 A2 ; AH Ford-Moore et al., Org. Synth 31 (1951) 111 ; M. Sekine et al., Bull. Chem. Soc. Jpn. 55 (1982) 239-242 and are commercially available, for example from Sigma Aldrich Chemie GmbH, Eschenstr. 5, 82024 Taufkirchen.

The organophosphorus compounds (E) according to the invention are used in the crosslinkable silicone compositions in amounts of preferably 0.001 to 10,000 ppm by weight, preferably 1 to 1,000 ppm by weight, in each case based on the total weight of the silicone compositions.

• R gleich oder verschieden ist und einen einwertigen, gegebenenfalls substituierten, von aliphatischen Kohlenstoff-Kohlenstoff-Mehrfachbindungen freien Si-C-gebundenen Kohlenwasserstoffrest mit 1 bis 18 Kohlenstoffatomen je Rest bedeutet und
• R¹ gleich oder verschieden ist und einen einwertigen Si-C-gebundenen Kohlenwasserstoffrest mit terminaler, aliphatischer Kohlenstoff-Kohlenstoff-Mehrfachbindung mit 2 bis 10 Kohlenstoffatomen je Rest bedeutet,
• a 0, 1, 2 oder 3 ist,
• b 0, 1 oder 2 ist
• und die Summe a+b≤3 ist,
• mit der Maßgabe, dass die Organopolysiloxane mindestens 2 Reste R¹ enthalten.

In the crosslinkable silicone compositions according to the invention, linear or branched or resinous organopolysiloxanes composed of units of the formula are preferably used as organosilicon compounds (A) which have Si-C-bonded radicals with aliphatic carbon-carbon multiple bonds

R _a R ¹ _b SiO _{(4-ab) / 2} (IV),

used, where

• R is the same or different and is a monovalent, optionally substituted, aliphatic carbon-carbon multiple bond-free Si-C-bonded hydrocarbon radical having 1 to 18 carbon atoms per radical and
• R ^{1 is} identical or different and is a monovalent Si-C-bonded hydrocarbon radical with a terminal, aliphatic carbon-carbon multiple bond with 2 to 10 carbon atoms per residue means
• a is 0, 1, 2 or 3,
• b is 0, 1 or 2
• and the sum is a + b≤3,
• with the proviso that the organopolysiloxanes contain at least 2 radicals R ¹ .

Examples of unsubstituted radicals R are alkyl radicals, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl -, neo-pentyl, tert-pentyl, hexyl, such as the n-hexyl, heptyl, such as the n-heptyl, octyl, such as the n-octyl and iso-octyl, such as the 2,2,4-trimethylpentyl, Nonyl radicals, such as the n-nonyl radical, decyl radicals, such as the n-decyl radical; Alkenyl radicals, such as the vinyl, allyl, n-5-hexenyl, 4-vinylcyclohexyl and 3-norbornenyl radical; Cycloalkyl radicals, such as cyclopentyl, cyclohexyl, 4-ethylcyclohexyl, cycloheptyl, norbornyl and methylcyclohexyl radicals; Aryl radicals, such as the phenyl, biphenylyl, naphthyl radical; Alkaryl groups such as o-, m-, p-tolyl groups and ethylphenyl groups; Aralkyl radicals, such as the benzyl radical, the alpha and the beta-phenylethyl radical.

Examples of substituted hydrocarbon radicals as the radicals R are halogenated hydrocarbons, such as the chloromethyl, 3-chloropropyl, 3-bromopropyl, 3,3,3-trifluoropropyl and 5,5,5,4,4,3,3-hexafluoropentyl radical and the Chlorophenyl, dichlorophenyl and trifluorotolyl.

R preferably has 1 to 6 carbon atoms. Preferred examples of radicals R are the methyl and phenyl radicals.

Examples of radicals R ¹ are the vinyl, allyl, methallyl, 1-propenyl, 5-hexenyl, ethynyl, butadienyl, hexadienyl, cyclopentenyl, cyclopentadienyl and cyclohexenyl radical, with the vinyl and allyl radical being preferred is.

Component (A) can also be a mixture of different organopolysiloxanes containing alkenyl groups, which differ, for example, in the alkenyl group content, the type of alkenyl group or structurally.

The structure of the organopolysiloxanes (A) containing alkenyl groups can be linear, cyclic or else branched or resinous. The content of trifunctional and / or tetrafunctional units leading to branched organopolysiloxanes is typically very low, preferably at most 20 mol%, in particular at most 0.1 mol%.

• wobei R und R¹ die oben dafür angegebene Bedeutung haben,
• d 0, 1, 2 oder 3, bevorzugt 1, bedeutet,
• m 0 oder eine ganze Zahl von 1 bis 200 ist und
• n 0 oder eine ganze Zahl von 1 bis 1800 ist,
• mit der Maßgabe, dass die Organopolysiloxane der Formel (V) mindestens zwei Reste R¹ enthalten.

Preferred organosilicon compounds (A) are organopolysiloxanes of the formula

R ¹ _d R _3-d SiO (SiR ₂ O) _n (SiRR ¹ O) _m SiR _3-d R ¹ _d (V)

• where R and R ^{1 have} the meaning given above,
• d represents 0, 1, 2 or 3, preferably 1,
• m is 0 or an integer from 1 to 200 and
• n is 0 or an integer from 1 to 1800,
• with the proviso that the organopolysiloxanes of the formula (V) contain at least two radicals R ¹ .

In the context of this invention, formula (V) should be understood such that n units - (SiR ₂ O) - and m units - (SiRR ¹ O) - can be distributed in any way in the organopolysiloxane molecule.

The organopolysiloxanes (A) have a viscosity at 25 ° C. of preferably 50 to 1,000,000 mPa · s, preferably 500 to 20,000 mPa · s. The viscosity is determined according to DIN 53029.

• R die oben dafür angegebene Bedeutung hat,
• e 0, 1, 2 oder 3,
• f 0, 1 oder 2
• und die Summe von e+f≤3 ist,
• mit der Maßgabe, dass die Organopolysiloxane mindestens 2 Si-gebundene Wasserstoffatome enthalten.

Linear, cyclic or branched organopolysiloxanes composed of units of the formula are preferably used as organosilicon compounds (B) which have Si-bonded hydrogen atoms

R _e H _f SiO _{(4-ef) / 2} (VI),

used, where

• R has the meaning given above,
• e 0, 1, 2 or 3,
• f 0, 1 or 2
• and the sum of e + f≤3 is
• with the proviso that the organopolysiloxanes contain at least 2 Si-bonded hydrogen atoms.

It is preferred to use an organosilicon compound (B) containing three or more SiH bonds per molecule. If an organosilicon compound (B) which has only two SiH bonds per molecule is used exclusively, the use of an organopolysiloxane (A) which has at least three alkenyl groups per molecule is recommended.

The hydrogen content of the organosilicon compound (B), which relates exclusively to the hydrogen atoms bonded directly to silicon atoms, is preferably in the range from 0.002 to 1.7% by weight of Si-bonded hydrogen, preferably from 0.008 to 1.7% by weight Si-bound hydrogen.

• R die oben dafür angegebene Bedeutung hat,
• x 0, 1 oder 2,
• y 0 oder eine ganze Zahl von 1 bis 1500 und
• z 0 oder eine ganze Zahl von 1 bis 200 ist,
• mit der Maßgabe, dass die Organopolysiloxane der Formel (VII) mindestens 2 Si-gebundene Wasserstoffatome enthalten.

Preferred organosilicon compounds (B) are organopolysiloxanes of the formula

H _x R _3-x SiO (SiR ₂ O) _y (SiRHO) _z SiR _3-x H _x (VII)

used, where

• R has the meaning given above,
• x 0, 1 or 2,
• y 0 or an integer from 1 to 1500 and
• z is 0 or an integer from 1 to 200,
• with the proviso that the organopolysiloxanes of the formula (VII) contain at least 2 Si-bonded hydrogen atoms.

In the context of this invention, formula (VII) is to be understood such that y units - (SiR ₂ O) - and z units - (SiRHO) - can be distributed in any way in the organopolysiloxane molecule.

The organosilicon compounds (B) used according to the invention have a viscosity at 25 ° C. of preferably 10 to 20,000 mPas, preferably 20 to 1,200 mPas.
The viscosity is determined according to DIN 53029

The organosilicon compound (B) is preferably used in amounts of 0.3 to 5.0 mol, preferably 0.45 to 3.0 mol, of Si-bonded hydrogen per mol of Si-bonded residue with aliphatic carbon-carbon multiple bond in the organosilicon compound ( A) used.

Instead of organosilicon compounds (A) and (B), organosilicon compounds (C) can also be used. As organosilicon compounds (C), the Si-C-bonded residues with aliphatic carbon-carbon multiple bonds and

• R und R¹ die oben dafür angegebene Bedeutung haben,
• h 0, 1, 2 oder 3,
• 1 0, 1 oder 2, und
• r 0, 1 oder 2 ist,
• mit der Maßgabe, dass die Organopolysiloxane mindestens zwei Reste R¹ und mindestens zwei Si-gebundene Wasserstoffatome enthalten.

Si-bonded hydrogen atoms, and can be used instead of organosilicon compounds (A) and (B), are preferably those from units of the formula

R _h SiO _{(4-h) / 2} (VIII), R ₁ R ¹ SiO _{(3-1) / 2} (IX) and R _r HSiO _{(3-r) / 2} (X),

used, where

• R and R ^{1 have} the meaning given above for this,
• h 0, 1, 2 or 3,
• 1 0, 1 or 2, and
• r is 0, 1 or 2,
• with the proviso that the organopolysiloxanes contain at least two radicals R ¹ and at least two Si-bonded hydrogen atoms.

Examples of organopolysiloxanes (C) are those composed of SiO _4/2 -, R ₃ SiO _1/2 -, R ₂ R ¹ SiO _1/2 - and R ₂ HSiO _1/2 - units, so-called MQ resins, these resins may additionally contain RSiO _3/2 and R ₂ SiO _2/2 units, and linear organopolysiloxanes consisting essentially of R ₂ R ¹ SiO _1/2 , R ₂ SiO _2/2 and RHSiO _2/2 units Around R ^{1 has the} same meaning as above.

The components (A), (B) and (C) used according to the invention can be produced commercially or by processes customary in chemistry.

eingesetzt, wobei

• Z ein Wasserstoffatom oder ein linearer oder verzweigter aliphatischer Kohlenwasserstoffrest, bevorzugt ein Methyl- oder Allylrest, oder ein Rest der Formel
  
          - (CR'₂)_g-SiR⁴ _oR⁵ _pR⁹ _q
  
  ist, wobei
• g eine ganze Zahl von 1 bis 8,
• o 0, 1 oder 2,
• p 0, 1, 2 oder 3 ist und
• q 0, 1, 2 oder 3 ist
• mit der Maßgabe, dass die Summe (o+p+q)≤93 ist,
• R' gleich oder verschieden ist und ein Wasserstoffatom oder einen monovalenten, unsubstituierten oder substituierten Kohlenwasserstoffrest, bevorzugt ein Wasserstoffatom, bedeutet,
• R^2a gleich oder verschieden ist und einen Alkyl-, Aryl-, Arylalkyl- oder Alkylarylrest, die durch Heteroatome, wie O-, N-, S oder P, unterbrochen sein können, bedeutet, wobei die Wasserstoffe durch Halogenatome oder Reste der Formel -SiR² ₃ substituiert sein können, wobei
• R² gleich oder verschieden ist und einen monovalenten, unsubstituierten oder substituierten, linearen, cyclischen oder verzweigten Kohlenwasserstoffrest bedeutet,
• R^2b gleich oder verschieden ist und ein Wasserstoffatom oder einen monovalenten, unsubstituierten oder substituierten, linearen oder verzweigten, aliphatisch gesättigten oder ungesättigten oder aromatisch ungesättigten Kohlenwasserstoffrest bedeutet, in dem einzelne Kohlenstoffatome durch O-, N-, S- oder P-Atome ersetzt sein können und die mit dem Cyclopentadienylrest annelierte Ringe bilden können, oder einer oder mehrere Reste R^2b einen Rest der Formel -SiR³ ₃ bedeuten kann, wobei
• R³ gleich oder verschieden ist und einen monovalenten, unsubstituierten oder substituierten, aliphatisch gesättigten Kohlenwasserstoffrest, der durch Heteroatome unterbrochen sein kann, oder einen aliphatisch ungesättigten, gegebenenfalls substituierten Kohlenwasserstoffrest oder einen über Sauerstoff angebundenen Siloxyrest bedeutet,
• R⁴ gleich oder verschieden ist und ein Wasserstoffatom oder einen monovalenten, unsubstituierten oder substituierten, linearen oder verzweigten, aliphatisch gesättigten oder ungesättigten oder aromatisch ungesättigten Kohlenwasserstoffrest, in dem einzelne Kohlenstoffatome durch O-, N-, S- oder P-Atome ersetzt sein können, bedeutet,
• R⁵ gleich oder verschieden ist und eine hydrolysierbare funktionelle Gruppe, ausgewählt aus der Gruppe von
  • Carboxy -O-C(O)R⁶,
  • Oxim -O-N=CR⁶ ₂,
  • Alkoxy -OR⁶,
  • Alkenyloxy -O-R⁸
  • Amid -NR⁶-C(O)R⁷,
  • Amin -NR⁶R⁷,
  • Aminoxy -O-NR⁶R⁷,
  bedeutet, wobei
• R⁶ gleich oder verschieden ist und ein H-Atom oder einen Alkyl-, Aryl-, Arylalkyl- oder Alkylarylrest bedeutet,
• R⁷ gleich oder verschieden ist und einen Alkyl-, Aryl-, Arylalkyl- oder Alkylarylrest bedeutet,
• R⁸ einen linearen oder verzweigten, aliphatisch ungesättigten organischen Rest, vorzugsweise Kohlenwasserstoffrest, bedeutet,
• R⁹ gleich oder verschieden ist und einen monovalenten linearen, cyclischen oder verzweigten, oligomeren oder polymeren siliciumorganischen Rest bedeutet, der eine oder mehrere Gruppen ausgewählt aus
  1. a) aliphatisch gesättigte oder ungesättigte Gruppen mit 1 bis 30 C-Atomen, in denen einzelne Kohlenstoffatome durch Hal, O-, N-, S- oder P-Atome ersetzt sein können,
  2. b) aromatische Gruppen mit 1 bis 30 C-Atomen, in denen einzelne Kohlenstoffatome durch Hal, O-, N-, S- oder P-Atome ersetzt sein können,
  3. c) Si-gebundene Wasserstoffatome
  4. d) Hydroxylgruppen und
  5. e) hydrolysierbare Gruppen
     enthalten kann.

Cyclopentadienyl complexes of platinum of the formula (XI) are preferably used as platinum catalysts (D)

used, where

• Z is a hydrogen atom or a linear or branched aliphatic hydrocarbon radical, preferably a methyl or allyl radical, or a radical of the formula
  
  - (CR ' ₂ ) _g -SiR ⁴ _o R ⁵ _p R ⁹ _q
  
  is where
• g is an integer from 1 to 8,
• o 0, 1 or 2,
• p is 0, 1, 2 or 3 and
• q is 0, 1, 2 or 3
• with the proviso that the sum (o + p + q) is ≤93,
• R 'is identical or different and denotes a hydrogen atom or a monovalent, unsubstituted or substituted hydrocarbon radical, preferably a hydrogen atom,
• R ^{2a is the} same or different and means an alkyl, aryl, arylalkyl or alkylaryl radical, which can be interrupted by heteroatoms, such as O-, N-, S or P, where the hydrogens are halogen atoms or radicals of the formula - SiR ² ₃ can be substituted, wherein
• R ^{2 is the} same or different and represents a monovalent, unsubstituted or substituted, linear, cyclic or branched hydrocarbon radical,
• R ^{2b is the} same or different and represents a hydrogen atom or a monovalent, unsubstituted or substituted, means linear or branched, aliphatically saturated or unsaturated or aromatically unsaturated hydrocarbon radical, in which individual carbon atoms can be replaced by O, N, S or P atoms and which can form fused rings with the cyclopentadienyl radical, or one or more radicals R. ^2b can mean a radical of the formula -SiR ³ ₃ , where
• R ^{3 is the} same or different and is a monovalent, unsubstituted or substituted, aliphatically saturated hydrocarbon radical which can be interrupted by heteroatoms, or an aliphatically unsaturated, optionally substituted hydrocarbon radical or a siloxy radical bonded via oxygen,
• R ^{4 is the} same or different and is a hydrogen atom or a monovalent, unsubstituted or substituted, linear or branched, aliphatically saturated or unsaturated or aromatically unsaturated hydrocarbon radical in which individual carbon atoms can be replaced by O, N, S or P atoms means
• R ^{5 is the} same or different and is a hydrolyzable functional group selected from the group of
  • Carboxy -OC (O) R ⁶ ,
  • Oxime -ON = CR ⁶ ₂ ,
  • Alkoxy -OR ⁶ ,
  • Alkenyloxy -OR ⁸
  • Amide -NR ⁶ -C (O) R ⁷ ,
  • Amine -NR ⁶ R ⁷ ,
  • Aminoxy -O-NR ⁶ R ⁷ ,
  means where
• R ^{6 is} identical or different and represents an H atom or an alkyl, aryl, arylalkyl or alkylaryl radical,
• R ^{7 is the} same or different and represents an alkyl, aryl, arylalkyl or alkylaryl radical,
• R ^{8 represents} a linear or branched, aliphatic unsaturated organic radical, preferably a hydrocarbon radical,
• R ^{9 is the} same or different and represents a monovalent linear, cyclic or branched, oligomeric or polymeric organosilicon radical which one or more groups selected from
  1. a) aliphatically saturated or unsaturated groups with 1 to 30 C atoms, in which individual carbon atoms can be replaced by Hal, O, N, S or P atoms,
  2. b) aromatic groups with 1 to 30 C atoms, in which individual carbon atoms can be replaced by Hal, O, N, S or P atoms,
  3. c) Si-bonded hydrogen atoms
  4. d) hydroxyl groups and
  5. e) hydrolyzable groups
     may contain.

Examples of R ⁴ are alkyl radicals, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, tert-butyl, n-pentyl , sec-pentyl, iso-pentyl, neo-pentyl, tert-pentyl; Hexyl radicals, such as the n-hexyl radical; Heptyl residues, such as the n-heptyl residue; Octyl radicals, such as the n-octyl radical and iso-octyl radicals, such as the 2,4,4-trimethylpentyl radical; Nonyl radicals, such as the n-nonyl radical; Decyl radicals, such as the n-decyl radical; Dodecyl radicals, such as the n-dodecyl radical; Hexadecyl radicals, such as the n-hexadecyl radical; Octadecyl radicals, such as the n-octadecyl radical; Cycloalkyl radicals, such as the cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl radical; Alkenyl radicals, such as the vinyl, 1-propenyl, 2-propenyl, n-5-hexenyl, 4-vinylcyclohexyl and the 3-norbornenyl radical; Aryl radicals, such as the phenyl, naphthyl, Anthryl and phenanthryl; Alkaryl radicals, such as the o-, m- and p-tolyl, xylyl, mesitylenyl and o-, m- and p-ethylphenyl radicals; and aralkyl radicals such as the benzyl radical, the α- and the β-phenylethyl radical.

Examples of substituted radicals R ⁴ are haloalkyl radicals, such as the 3,3,3-trifluoro-n-propyl radical, the 2,2,2,2 ', 2', 2'-hexafluoroisopropyl radical and the heptafluoroisopropyl radical, and haloaryl radicals, such as the o -, m- and p-chlorophenyl.

The radical R ⁴ is preferably monovalent hydrocarbon radicals having 1 to 30 carbon atoms which can be interrupted by heteroatoms, such as O-, N-, S or P, particularly preferably monovalent, aliphatic saturated hydrocarbon radicals having 1 or 8 carbon atoms, in particular around the methyl or phenyl radical, very particularly preferably around the methyl radical.

Preferred radicals R ⁵ are carboxy radical and alkoxy radicals, methoxy and ethoxy radicals being particularly preferred.

The radical R ⁹ is preferably siloxy radicals bonded via oxygen.

Examples of siloxy residues R ⁹ are linear or branched oligo and polysiloxy residues with 1 to 5000 siloxy units, which contain dimethylsiloxy, phenylmethylsiloxy, diphenylsiloxy, methylsiloxy, phenylsiloxy or SiO _4/2 units and hydroxyl, trimethylsilyl, dimethylsilyl or carry vinyl end groups.

The siloxy radicals R ^{9 are} preferably those of the formula

- (OSiR ^9a ₂ ) _m -R ^9a (XII),

where m is an integer from 1 to 5000, preferably 8 to 1000, and R ^{9a may be the} same or different and has a meaning given for radical R ⁴ .

• R^9b ein Methyl- oder Phenylrest ist und
• R^9c ein Methyl-, Vinyl- oder Hydroxyrest oder ein Si-gebundenes H-Atom ist.

Preferred examples of siloxy radicals R ⁹ are those of the formula

- (OSiR ^9b ₂ ) _m -R ^9c (XIIa),

where m has the meaning given above,

• R ^{9b is} a methyl or phenyl radical and
• R ^{9c is} a methyl, vinyl or hydroxyl radical or an Si-bonded H atom.

Examples of radical R 'are the hydrogen atom and the examples given for unsubstituted radical R ⁴ .

Preferred radicals R ^2a are aliphatic hydrocarbon radicals with 1 to 30 C atoms which are optionally substituted with halogen atom, silyl radical or aryl radical and which can be interrupted by heteroatoms such as O, N, S or P, particularly preferably linear and branched alkyl radicals with 1 to 12 Carbon atoms, especially the methyl radical.

The radical R ^2b is preferably an optionally substituted hydrocarbon radical which can be interrupted by heteroatoms and which is mono- or polyvalent, preferably monovalent. Two or more monovalent radicals R ^2b can also form one or more rings which are fused to the cyclopentadienyl radical and can be aromatic, saturated or aliphatic unsaturated. A polyvalent radical R ⁴ can also be used be bonded to the cyclopentadienyl radical via more than one position and form one or more rings which are fused to the cyclopentadienyl radical and can be aromatic, saturated or aliphatic unsaturated.

Examples of radical R ^2b are the examples given for radicals R ⁴ for monovalent, optionally substituted hydrocarbon radicals and SiC-bonded silyl radicals -SiR ³ ₃ , such as trialkylsilyl radicals. Examples of fused rings formed by linked monovalent or divalent radicals R ^2b are benzo, naphtho, cyclopenta or cyclohexa groups.

The radical R ^2b is preferably a hydrogen atom or monovalent hydrocarbon radicals having 1 to 30 carbon atoms which are optionally substituted by halogen atoms and which can be interrupted by heteroatoms, such as O-, N-, S or P, or benzo radicals or trialkylsilyl radicals, particularly preferably around a hydrogen atom or monovalent, aliphatically saturated hydrocarbon radicals having 1 or 8 carbon atoms or benzo radicals, in particular around a hydrogen atom or the methyl radical.

The radical R ^2b can also be a radical of the formula -SiR ³ ₃ . The radical R ³ is preferably monovalent, aliphatic, saturated hydrocarbon radicals having 1 to 30 carbon atoms which are optionally substituted by halogen atoms and which can be interrupted by heteroatoms such as O-, N-, S or P, particularly preferably monovalent, aliphatic saturated hydrocarbon radicals with 1 or 8 carbon atoms, in particular around the methyl or phenyl radical, very particularly preferably around the methyl radical.

Examples of aliphatic unsaturated hydrocarbon radicals R ³ are the examples given for radical R ⁴ for optionally substituted, aliphatic unsaturated hydrocarbon radicals.

Preferred examples of aliphatic unsaturated hydrocarbon radicals R ³ are radicals of the formula -CR " ₂ -CR" = CR " ₂ , where R" can be the same or different and has a meaning given for radical R '.

The radical R "is preferably hydrogen atom or hydrocarbon radicals having 1 to 30 carbon atoms, particularly preferably hydrogen atom or linear saturated hydrocarbon radicals having 1 to 8 carbon atoms, in particular methyl radical or hydrogen atom, very particularly preferably hydrogen atom.

The radical R ³ can also be a siloxy radical attached via oxygen. Examples of siloxy radicals R ⁹ , including those of the formulas (XII) and (XIIa), also apply to siloxy radicals R ³ .

If R ^{2b is} a radical of the formula -SiR ³ ₃ , then preferred examples are the trimethylsilyl radical, the dimethylallyl radical and siloxy radicals of the formula (XIIa).

The methylcyclopentadienyltrimethylplatinum complex (MeCp (PtMe ₃ )) is particularly preferred as the platinum catalyst (D).

The platinum catalysts (D) and their production are, for example, in US 8,088,878 B2 and WO 2016/030325 A1 described.

The platinum catalyst (D) can be used in any form, for example also in the form of Hydrosilylation catalyst containing microcapsules, or organopolysiloxane particles, as in US 6,251,969 B1 described.

The content of platinum catalyst (D) is preferably chosen so that the silicone composition according to the invention has a content of platinum metal from 0.1 to 200 ppm by weight, preferably from 0.5 to 80 ppm by weight.

In addition to the above-mentioned components (A), (B), (C), (D) and (E), other substances, such as fillers (F) and additives (G), may also be present in the silicone compositions according to the invention.

The silicone compositions are preferably transparent below 500 nm, particularly preferably from 200 to 400 nm, so that light-induced crosslinking of the silicone composition can take place by activating the platinum catalyst (D). The silicone compositions are therefore preferably free of light-absorbing fillers.

However, the silicone composition can also contain filler (F). Examples of non-reinforcing fillers (F) are fillers with a BET surface area of up to 50 m ² / g, such as quartz, diatomaceous earth, calcium silicate, zirconium silicate, zeolites, metal oxide powder, such as aluminum, titanium, iron, or zinc oxides or their mixed oxides, barium sulfate, calcium carbonate, gypsum, silicon nitride, silicon carbide, boron nitride, glass and plastic powder. Reinforcing fillers, that is fillers with a BET surface area of at least 50 m ² / g, are, for example, pyrogenically produced silica, precipitated silica, carbon black, such as furnace black and acetylene black, and silicon-aluminum mixed oxides with a large BET surface area. Fibrous fillers include asbestos as well Plastic fibers. The fillers mentioned can be hydrophobicized, for example by treatment with organosilanes or organosiloxanes or by etherification of hydroxyl groups to alkoxy groups. It can be a type of filler, a mixture of at least two fillers can also be used.

If the silicone compositions according to the invention contain fillers (F), their proportion is preferably 2 to 60% by weight, in particular 5 to 50% by weight, in each case based on the total weight of the silicone composition according to the invention.

Examples of components (G) which may be used are all further additives which have also hitherto been used to prepare addition-crosslinkable compositions, such as resinous polyorganosiloxanes which are different from the siloxanes (A), (B) and (C), plasticizers, fungicides, Fragrances, rheology additives, corrosion inhibitors, oxidation inhibitors, organic flame-retardant agents and agents for influencing the electrical properties that differ from the fillers (F), dispersing agents, solvents, adhesion promoters, color additives, crosslinking aids, plasticizers, which are derived from the siloxanes (A), (B) and (C) are different, and heat stabilizers.

The additives (G) are preferably color additives, rheology additives, adhesion promoters, crosslinking aids and mixtures thereof.

If the silicone compositions according to the invention contain additives (G), they are amounts of preferably 0 to 40% by weight, particularly preferably 1 to 20% by weight, in particular 1 to 5% by weight, in each case based on the total weight of the silicone compositions according to the invention.

The components used according to the invention can each be a type of such a component or a mixture of at least two types of a respective component.

The compositions according to the invention can be prepared in any manner known per se, such as by methods and mixing methods as are customary for the preparation of addition-crosslinking compositions.

Another object of the present invention is a method for producing the compositions according to the invention by mixing the individual components in any order.

This mixing can take place at room temperature and the pressure of the surrounding atmosphere, ie about 900 to 1100 hPa.

The mixing according to the invention is preferably carried out with the exclusion of moisture and light with a wavelength of less than 400 nm.

The process according to the invention can be carried out continuously or batchwise.

In a preferred embodiment of the process according to the invention, a mixture of platinum catalyst (D) and component (E) with components (A), (B) and optionally (F) and optionally (G) are mixed uniformly. The platinum catalyst (D) used according to the invention can be a substance or a solution in a suitable solvent, preferably dissolved in a small amount (A), and mixed with (E).

The compositions according to the invention can be both one-component silicone compositions and two-component silicone compositions. In the latter case, the two components of the compositions according to the invention can contain all constituents in any proportions. A component preferably contains the platinum catalyst (D) and no Si-H-containing component (B) or (C).

The crosslinking is preferably carried out at room temperature, preferably at 15 ° C. to 30 ° C., and the pressure of the surrounding atmosphere, that is to say approximately 900 to 1100 hPa.

The crosslinking is preferably initiated by irradiation, in particular by ultraviolet radiation (UV) at 200 to 400 nm, in particular 250 to 350 nm. Depending on the formulation, the catalyst and the intensity of the UV radiation, the necessary irradiation time can preferably be less than 5 minutes, particularly preferably 10 seconds and less. Any radiation source that has radiation components below about 400 nm can be used. Wavelengths smaller than 200 nm are preferably not to be used. Conventional low, medium and high pressure mercury lamps are suitable. Radiation sources such as fluorescent tubes and "black light lamps" are also suitable.

The silicone compositions according to the invention have the advantage that, surprisingly, the addition of the phosphorus compounds according to the invention means that they can be stored well with the exclusion of light, the viscosities exceeding one another do not change a long storage time, the gelling times remain constant and the crosslinkable masses therefore show no tendency to vulcanize. This has the further advantage that they can also be used as one-component systems. Unexpectedly, the crosslinking begins immediately and quickly when irradiated and the crosslinking rate is not impaired or remains almost unaffected, despite the use of the phosphorus compounds according to the invention, which are known as inhibitors. The phosphorus compounds according to the invention are deactivated by the radiation.

The phosphorus compounds according to the invention differ surprisingly from other known inhibitors of platinum catalysts, such as ethynylcyclohexanol or 1,3-divinyltetramethyldisiloxane, with which no stabilization with the exclusion of UV light is achieved when UV-crosslinking silicone compositions are stored.

The silicone compositions according to the invention also have the advantage that the crosslinking at room temperature - thus low-energy - takes place only by a relatively short irradiation with UV light, and no elevated temperatures are necessary, so that the silicone compositions according to the invention are applied to temperature-sensitive substrates, for example in electronics and Electronics and medical technology can be used, applied and vulcanized.

Another object of the invention is the use of the crosslinkable silicone compositions for the production of moldings, potting materials, adhesives or coatings.

They are produced by crosslinking the silicone compositions according to the invention by irradiation with light, in particular UV light.

The invention further relates to a process for crosslinking the silicone compositions according to the invention by irradiation with light, preferably UV light, the organophosphorus compounds (E) losing their inhibitory action through deactivation and crosslinking the silicone compositions.

Examples

Examples are now shown with organophosphorus compounds which demonstrate the positive effect of the substances mentioned on the storage stability of UV-crosslinking silicone compositions when stored in the absence of light.

A gelling time test using a so-called gel timer was used as a measure of the storage stability, which runs at 120 ° C. and with the exclusion of UV light.

Comparative experiment 1:

250 ml of a mixture of 491 ppm trimethyl (methyl-cyclopentadienyl) platinum (IV) ( CAS number 94442-22-5 ; available for example from Sigma Aldrich Chemie GmbH, Eschenstr. 5, 82024 Taufkirchen) in a silicone polymer (vinyl-terminated polydimethylsiloxane, with a viscosity of 1000 mPas at 25 ° C), corresponding to 300 ppm platinum, which is obtained by diluting an 8.18% by weight concentrate (= 5% by weight Platinum) was produced, is stored under the exclusion of UV light. After defined intervals, the gel time is set at 120 ° C using a gel timer (GELNORM, Saur) based on DIN 16 945 determined. The gel time is the time between the start of the test and the time at which the catalyzed mass changes from the liquid to the gel-like state. This determination is made under the exclusion of UV light.
To determine the gelation time, an SiH-linked polydimethylsiloxane, in which the proportion of Si-bonded hydrogen is 12 mol%, is added to the catalyst mixture in a weight ratio of 9: 1 and mixed in at 200 rpm in a laboratory paddle stirrer for 15 min. The results are summarized in Table 1.

Examples 1 to 5:

1. (1) Triethylphosphit ( CAS-Nr. 122-52-1 )
2. (2) Triphenylphosphin ( CAS-Nr. 603-35-0 )
3. (3) Tris(2,4-di-tert-butylphenyl)phosphit ( CAS-Nr. 31570-04-4 )
4. (4) Tris(tert-butyldimethylsilyl)phosphit ( CAS-Nr. 85197-27-9 )
5. (5) 3,9-Bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecan ( CAS-Nr.3806-34-6 )

In Examples 1 to 5, the same series of tests is carried out as in Comparative Experiment 1 above, with the addition of the catalyst concentrate in the vinyl-terminated polydimethylsiloxane then adding the corresponding amount of the organophosphorus compound, with 1 hour stirring at 200 rpm using a laboratory paddle stirrer (RE 162, from Janke and Kunkel) and then filtered through a 120 µm sieve.
The gel time is determined as described in comparative experiment 1. The following organophosphorus compounds were tested:

1. (1) triethyl phosphite ( CAS number 122-52-1 )
2. (2) triphenylphosphine ( CAS number 603-35-0 )
3. (3) tris (2,4-di-tert-butylphenyl) phosphite ( CAS number 31570-04-4 )
4. (4) tris (tert-butyldimethylsilyl) phosphite ( CAS number 85197-27-9 )
5. (5) 3,9-bis (octadecyloxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane ( CAS No. 3806-34-6 )

(1) to (5) are available from Sigma Aldrich Chemie GmbH, Eschenstr. 5, 82024 Taufkirchen

The results are summarized in Table 1. Table 1: Gelation time test with organophosphorus compounds according to the invention Storage period Comparative experiment 1 example 1 Example 2 Example 3 Example 4 Example 5 Without addition 300 ppm by weight (1) triethyl phosphite 300 ppm by weight (2) triphenylphosphine 300 ppm by weight (3) tris (2,4-di-tert-butylphenyl) phosphite 300 ppm by weight (4) tris (tert-butyldimethylsilyl) phosphite 300 ppm by weight (5) 3,9-bis (octa-decyloxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane right away 11:48 min 3h 30min 7h 37min 1h 30min 11h 38min 1h 39min 1 week 07:50 min 3h 21min 4h 13 min 1h 29min 13h 31min 1h 19min 4 weeks 05:21 min 1h 41min 4h 45min 1h 30min 15h 55min 1h 8min 8 weeks 04:20 min 1h 53min 3h 29min 1h 21min 15h 2min 1h 18min 3 months 03:49 min 1h 56min 3h 49min 1h 19min 12h 24min 1h 16min 4 months 03:00 min 2h 3min 3h 36min 1h 16min 12h 24min 1h 15min 5 months - 2h 16min 3h 31min 1h 8min 11h 20min 1h 12min 6 months - 2h 14min 4h 19min 1h 3min - -

As can be seen in Table 1, the phosphorus compounds according to the invention, in comparison with the mixture without the addition of a phosphorus compound, lead to an extension of the gelling time to partly different but very high levels and thus to a stabilization over several months.

• Triphenylphosphit
• Tris(2-tert-butyl-4-methylphenyl)phosphit
• Tris(1-adamantanemethyl)phosphit
• Triisopropylphosphit
• Triisodecylphosphit
• Tris(2-ethylhexyl)phosphit
• 3,9-bis(2,4-ditert-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane
• Distearylpentaerythritdiphosphit
• Bis(2,6-di-tertbutyl-4-methylphenyl)-pentaerythritdiphosphit
• Tris(nonylphenyl)phosphit
• Tris[(2-phenyl)phenyl]phosphit
• Tris[(3-phenyl)phenyl]phosphit
• Tris[(4-phenyl)phenyl]phosphit
• Tris[(5-phenyl)phenyl]phosphit
• Tris[(6-phenyl)phenyl]phosphit
• Tris[(2,4-diphenyl)phenyl]phosphit
• Tris[(2,6-diphenyl)phenyl]phosphit
• Tris[(3,5-diphenyl)phenyl]phosphit
• Tris(2,6-diisopropylphenyl)phosphit
• Tris(2-methylphenyl)phosphit
• Tris(2,4-dioctylphenyl)phosphit
• Tri(o-tolyl)phosphit
• Tricyclohexylphosphit
• Trilaurylphosphit
• Diisodecylphenylphosphit
• 2-Ethylhexyldiphenylphosphit
• Benzyldiphenylphosphin
• tert-Butyldiphenylphosphin
• Cyclohexyldiphenylphosphin
• Tri-n-butylphosphin
• Tri-tertbutyl-phosphin
• Tri-o-tolyl-phosphin
• Tri(p-tolyl)phosphin
• Tricylohexylphosphin
• Dimethylphenylphosphin
• Tris(trimethylsilyl)phosphine

The five organophosphorus compounds according to Examples 1-5 are examples of an entire group of substances. Examples of other phosphorus compounds now follow. The experiments described in Examples 1-5 can also be carried out with these compounds. A similar effect on storage stability can be expected:

• Triphenyl phosphite
• Tris (2-tert-butyl-4-methylphenyl) phosphite
• Tris (1-adamantanemethyl) phosphite
• Triisopropyl phosphite
• Triisodecyl phosphite
• Tris (2-ethylhexyl) phosphite
• 3,9-bis (2,4-di-tert-butylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane
• Distearylpentaerythritol diphosphite
• Bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite
• Tris (nonylphenyl) phosphite
• Tris [(2-phenyl) phenyl] phosphite
• Tris [(3-phenyl) phenyl] phosphite
• Tris [(4-phenyl) phenyl] phosphite
• Tris [(5-phenyl) phenyl] phosphite
• Tris [(6-phenyl) phenyl] phosphite
• Tris [(2,4-diphenyl) phenyl] phosphite
• Tris [(2,6-diphenyl) phenyl] phosphite
• Tris [(3,5-diphenyl) phenyl] phosphite
• Tris (2,6-diisopropylphenyl) phosphite
• Tris (2-methylphenyl) phosphite
• Tris (2,4-dioctylphenyl) phosphite
• Tri (o-tolyl) phosphite
• Tricyclohexyl phosphite
• Trilauryl phosphite
• Diisodecylphenyl phosphite
• 2-ethylhexyl diphenyl phosphite
• Benzyldiphenylphosphine
• tert -butyldiphenylphosphine
• Cyclohexyldiphenylphosphine
• Tri-n-butylphosphine
• Tri-tertbutyl phosphine
• Tri-o-tolyl-phosphine
• Tri ( p -tolyl) phosphine
• Tricylohexylphosphine
• Dimethylphenylphosphine
• Tris (trimethylsilyl) phosphine

Comparative experiments 2 to 5:

The gelation time test is carried out as described in Examples 1 to 5. Instead of the phosphorus compound according to the invention, however, 1,3-divinyltetramethyldisiloxane or ethinylcyclohexanol, which are known inhibitors for platinum catalysts according to the prior art, were added in the amounts given in Tables 2 and 3 (comparative tests 2/3 and 4/5) . Comparative experiment 1 served as a reference. The results are summarized in Tables 2 and 3, respectively. Table 2: Gelation time test with 1,3-divinyltetramethyldisiloxane Storage period Comparative experiment 1 Comparative experiment 2 Comparative experiment 3 Without addition With 240 ppm by weight additive With 480 ppm by weight additive right away 11:48 min 22:12 min 31:00 min 1 week 07:50 min 16:01 min 22:00 min 4 weeks 05:21 min 5:30 min 8:00 min 8 weeks 04:20 min 4:49 min 6:21 min 3 months 03:49 min 3:29 min 4:31 min 4 months 03:00 min 3:27 min 4:17 min 5 months - 3:20 min 4:09 min 6 months - 2:49 min 3:49 min Storage period Comparative experiment 1 Comparative experiment 4 Comparative experiment 5 Without addition With 5 ppm by weight addition With 14 ppm by weight addition right away 11:48 min 13:41 min 1 h 47 min 1 week 07:50 min 7:41 min 44:10 min 4 weeks 05:21 min 3:32 min 10:20 min 8 weeks 04:20 min 3:29 min 10:41 min 3 months 03:49 min 3:28 min 7:31 min 4 months 03:00 min 3:19 min 8:30 min 5 months - - 8:40 min 6 months - - 8:00 min

When 1,3-divinyltetramethyldisiloxane and ethynylcyclohexanol are added, which are used in the prior art to regulate the rate of crosslinking, the storage stability decreases significantly after one week. A permanently stable state cannot be achieved, as with the addition of the organophosphorus compounds according to the invention.

Comparative experiment 6 and 7:

The gelation time test is carried out as described in Examples 1 to 5. Instead of the phosphorus compound according to the invention, however, trioctylamine or 1,3-divinyltetramethyldisilazane, inhibitors for platinum catalysts according to the prior art, were added in the amount given in Tables 4 and 5 (comparative experiment 6 and 7). Comparative experiment 1 served as a reference. The results are summarized in Tables 4 and 5, respectively. Table 4: Gel time test with trioctylamine Storage period Comparative experiment 1 Comparative experiment 6 Without addition With 300 ppm by weight additive right away 11:48 min 14:02 min 1 week 07:50 min 4:59 min 4 weeks 05:21 min 2:38 min 8 weeks 04:20 min - 3 months 03:49 min - 4 months 03:00 min - 5 months - - Storage period Comparative experiment 1 Comparative experiment 7 Without addition With 10 ppm by weight addition right away 11:48 min 14:10 min 1 week 07:50 min 3:50 min 4 weeks 05:21 min 3:39 min 8 weeks 04:20 min 2:38 min 3 months 03:49 min - 4 months 03:00 min - 5 months - -

When 1,3-divinyltetramethyldisilazane and trioctylamine are added, the mixtures are not stable in storage and even lead to greater instability than with the mixtures without addition. Apparently these substances lead to an irreversible destruction of the UV-active platinum complex.

Comparative Experiment 8 and Examples 6 to 8:

• Temperatur: 25 °C
• Messart: Oszillation
• Messspalt: 0,2 mm
• Deformation: 0,1%
• Frequenz: 0,5 Hz
• Probevolumen: 0,4 ml

To evaluate the UV activity, the pot life (= time to reach a viscosity of 300,000 mPas at 25 ° C) was measured in accordance with ISO 6721-10 (complex shear viscosity using a parallel plate vibration rheometer) in a rheometer from Anton Paar MCR 302 after 60 Irradiation with 6 mW for seconds (lamp: Omnicure S1000, 320-500 nm; distance to sample: 22mm) determined from the following mixture:
Mixture of 9.1% by weight of a catalyst mixture of trimethyl (methylcyclopentadienyl) platinum (IV) described in Examples 1-5 in a silicone polymer (vinyl-terminated polydimethylsiloxane, viscosity 1000 mPas at 25 ° C.), the in Table 6 mentioned organophosphorus compounds (Examples 6-8, amounts based on the final composition) or without Addition (comparative experiment 8) and 90.9% by weight of a preparation which can be crosslinked by hydrosilylation and contain linear and branched SiH- and vinyl-functional siloxanes (commercially available under the name SEMICOSIL® 912 from Wacker Chemie AG, D-Munich).
Mixing time for 22 g batch size: 20 s at 2500 rpm with Speed Mixer DAC 150 FV, from Hauschild.
Device settings from Anton Paar MCR 302:

• Temperature: 25 ° C
• Measurement type: oscillation
• Measuring gap: 0.2 mm
• Deformation: 0.1%
• Frequency: 0.5 Hz
• Sample volume: 0.4 ml

In addition, the catalyst mixture with organophosphorus compound according to the invention was stored for 6 months at 25 ° C. with exclusion of light and then the pot life after adding the above-mentioned crosslinkable preparation of SiH- and vinyl-functional siloxanes (SEMICOSIL® 912 from Wacker-Chemie) was determined, analogously to described above. The results are summarized in Table 6.

The hardness is determined by a penetration measurement in accordance with DIN ISO 2137 (penetrometer PNR 12, Saur, Anton-Paar, cone 9.38 g, penetration time 5 sec). For this purpose, 50 g of the above-mentioned mixture for assessing the UV activity (mixing parameters: 100 g mixture in 150 ml beaker in a Speedmixer DAC 150 FV, from Hauschild, 60 sec at 2500 rpm) are placed in a 125 ml beaker and after irradiation with 70 mW / cm ² (UVACUBE 2000, Fa. Hönle, 230-400 nm) vulcanized for 10 sec and annealing at 30 min / 150 ° C. The results are summarized in Table 6. Table 6: Compare experiment 8 Example 6 Example 7 Example 8 Without addition With (1) triethyl phosphite (27 ppm by weight) With (2) triphenylphosphine (27 ppm by weight) With (3) tris (2,4-di-tert-butylphenyl) phosphite (27 ppm by weight) Pot life 372 s 717 s 797 s 665 s penetration 58 1/10 mm 62 1/10 mm 63 1/10 mm 61 1/10 mm Pot life (6 months storage) 447 s 601 s 780 s 656 s

The mixtures vulcanize easily after UV irradiation, the slowing down of the crosslinking by the organophosphorus compounds used is within an acceptable range. The penetration of the vulcanizates is almost unchanged compared to the reference sample (without addition). The pot lives have hardly changed after 6 months of storage.

Example 9:

In further experiments, a catalyst mixture containing 491 ppm by weight of trimethyl (methylcyclopentadienyl) platinum (IV) (= 300 ppm by weight of platinum) in vinyl-terminal polydimethylsiloxane with a viscosity was used to clarify the processes during the irradiation with UV light of 1000 mPas at 25 ° C) and different amounts of tris (2,4-di-tert-butylphenyl) phosphite and irradiated with 70 mW / cm ² for 10 sec. The content of tris (2,4-di-tert-butylphenyl) phosphite was determined before and after irradiation by means of ¹ H-NMR by evaluating the signal of the tert-butyl group (δ = 1.3 ppm, CDCl ₃ , 500 MHz, 300 K). The results are summarized in Table 7. Table 7: Salary before radiation Content after irradiation Tris (2,4-di-tert-butylphenyl) phosphite 288ppm 0 ppm Tris (2,4-di-tert-butylphenyl) phosphite 448 ppm 0 ppm Tris (2,4-di-tert-butylphenyl) phosphite 47 ppm 0 ppm

As can be seen in Table 7, the phosphorus compound is deactivated by the irradiation under the framework conditions typical for the crosslinking (irradiation intensity and duration) and can no longer be detected after the irradiation.

Comparative Experiment 9 and Examples 10 to 12:

One-component mixtures were also formulated with some of the organophosphorus compounds according to the invention and the viscosity development during storage was monitored. The mixtures were prepared as follows: In a 150 ml PE beaker, a mixture of 9.1% by weight of a catalyst mixture described in Examples 1-5 in a silicone polymer (vinyl-terminated polydimethylsiloxane) was described in Table 8 mentioned organophosphorus compounds in the amounts given in Table 8 (Examples 10-12, quantitative details based on the final composition) or without addition (Comparative Experiment 9) and 90.9% by weight of a preparation which can be crosslinked by hydrosilylation and comprise linear and branched SiH and vinyl functional siloxanes (commercially available under the name SEMICOSIL® 912 manufactured by Wacker Chemie AG, D-Munich), stirred in a speed mixer for 60 seconds at 2500 rpm and stored under the exclusion of light. After defined time intervals, the viscosity was increased with a Plate-cone viscometer (Anton-Paar MCR 302) determined according to DIN 53019 (measurement of viscosities and flow curves with rotary viscometers) (sample amount: 0.5 ml, measuring time: 3min, measured values: 30, cone CP50-2, temp. 25 ° C).
The results are summarized in Table 8. Table 8: Storage period Compare experiment 9 Example 10 Example 11 Example 12 Without addition 27 ppm by weight (2) triphenylphosph 27 ppm by weight (3) tris (2,4-di-tert-butylphenyl) phosphite 4.5 ppm by weight (3) tris (2,4-di-tert-butylphenyl) phosphite right away 1030 mPas 1090 mPas 1090 mPas 1100 mPas 3 days 1050 mPas 1090 mPas 1090 mPas 1090 mPas 9 weeks 3183 mPas 1099 mPas 1100 mPas 1090 mPas 12 weeks 6340 mPas 1140 mPas 1099 mPas 1111 mPas 1 - 3 weeks 7736 mPas 1093 mPas 1090 mPas 1101 mPas 14 weeks 8808 mPas 1096 mPas 1099 mPas 1094 mPas 16 weeks 13079 mPas 1095 mPas 1077 mPas 1092 mPas 17 weeks 15822 mPas 1102 mPas 1090 mPas 1110 mPas 19 weeks vulcanized 1105 mPas 1099 mPas 1099 mPas 25 weeks vulcanized 1132 mPas 1103 mPas 1121 mPas 28 weeks vulcanized 1149 mPas 1100 mPas 1107 mPas 30 weeks vulcanized 1167 mPas 1091 mPas 1116 mPas 36 weeks vulcanized 1223 mPas 1090 mPas 1112 mPas

When an organophosphorus compound according to the invention is added, the viscosity remains for a period of around 30 Stable for weeks, whereas with a mixture without additives a significant increase in viscosity can be seen after just a few weeks and complete vulcanization occurs after 19 weeks at the latest.

Claims (13)

1. Silicone compositions that can be crosslinked by irradiation with light, preferably UV light, comprising

   (A) organosilicon compounds comprising Si-C-bonded radicals having aliphatic carbon-carbon multiple bonds,

   (B) organosilicon compounds comprising hydrogen atoms bonded to Si
   or instead of (A) and (B)

   (C) organosilicon compounds comprising Si-C-bonded radicals having aliphatic carbon-carbon multiple bonds and hydrogen atoms bonded to Si,

   (D) platinum catalysts that can be activated by light of wavelength 200 to 500 nm, preferably UV light of wavelength 200 to 400 nm, selected from the group of cyclopentadienyl complexes of platinum and

   (E) organophosphorus compounds selected from the group of the formulae
   
           P(=O)_u[(OR¹⁰)]_s[R¹¹]_t     (I),
   
           P[(O)_iSiR¹² ₃]₃     (II),
   
   

   

   and mixtures thereof, wherein

   R¹⁰ and R¹¹ are the same or different and are in each case an alkyl radical of the formula C_jH_2j+1 where j = 2-31 or an alkenyl radical of the formula C_kH_2k-1 where k = 2-31 or an aryl or alkylaryl radical of the formula -(C₆H_5-w) - (C_vH_2v+1)_w where v = 1-18 and w = 0-5,

   R¹² is the same or different and is a monovalent hydrocarbon radical having 1 to 18 carbon atoms,

   R¹³ is a tetravalent hydrocarbon radical having 5 to 30 carbon atoms,

   R¹⁴ is the same or different and has the definition of R¹⁰,

   s is 0, 1, 2 or 3,

   t is 0, 1, 2 or 3,

   with the proviso that the sum of s+t = 3,

   u is 0 or 1, preferably 0, and

   i is 0 or 1, preferably 1.
2. Silicone compositions that can be crosslinked according to Claim 1, characterized in that the organophosphorus compounds (E) are used in amounts from 0.001 to 10 000 ppm by weight, preferably 1 to 1 000 ppm by weight, based in each case on the total weight of the silicone compositions.
3. Silicone compositions that can be crosslinked according to Claim 1 or 2, characterized in that R^{1
   0} is an ethyl, propyl, phenyl, nonylphenyl, dinonylphenyl, 2-ethylhexyl, 2,4-di-tert-butylphenyl radical or 2-tert-butyl-4-methylphenyl radical,
   R¹¹ is a phenyl radical,
   R¹² is a methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl or hexyl radical, preferably a methyl or tert-butyl radical,
   R¹³ is a radical of the formula C(CH₂)₄- and
   R¹⁴ is an octadecyl, 2,6-di-tert-butyl-4-methylphenyl or a 2,4-di-tert-butylphenyl radical.
4. Silicone compositions that can be crosslinked according to Claim 1, 2 or 3, characterized in that the organophosphorus compounds (E) used are tris(2,4-di-tert-butylphenyl) phosphite,
   triethyl phosphite, triphenylphosphine, tris(tert-butyldimethylsilyl) phosphite or 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane.
5. Silicone compositions that can be crosslinked according to any of Claims 1 to 4, characterized in that the organosilicon compounds (A) used are linear or branched or resinous organopolysiloxanes composed of units of the formula
   
           R_aR¹ _bSiO_(4-a-b)/2     (IV),
   
   wherein

   R is the same or different and is a monovalent, optionally substituted, Si-C-bonded hydrocarbon radical having 1 to 18 carbon atoms per radical, free of aliphatic carbon-carbon multiple bonds and

   R¹ is the same or different and is a monovalent SiC-bonded hydrocarbon radical, comprising 2 to 10 carbon atoms per radical, having a terminal, aliphatic carbon-carbon multiple bond,

   a is 0, 1, 2 or 3,

   b is 0, 1 or 2

   and the sum of a+b is ≤3,

   with the proviso that the organopolysiloxanes comprise at least 2 radicals R¹.
6. Silicone compositions that can be crosslinked according to any of Claims 1 to 5, characterized in that the organosilicon compounds (A) used are organopolysiloxanes of the formula
   
           R¹ _dR_3-dSiO(SiR₂O)_n(SiRR¹O)_mSiR_3-dR¹ _d     (V),
   
   wherein

   R and R¹ have the definition specified therefor in Claim 5,

   d is 0, 1, 2 or 3, preferably 1,

   m is 0 or an integer from 1 to 200 and

   n is 0 or an integer from 1 to 1800,

   with the proviso that the organopolysiloxanes of the formula (V) comprise at least two radicals R¹.
7. Silicone compositions that can be crosslinked according to any of Claims 1 to 6, characterized in that the organosilicon compounds (B) used are linear, cyclic or branched organopolysiloxanes composed of units of the formula
   
           R_eH_fSiO_(4-e-f)/2     (VI),
   
   wherein

   R has the definition specified therefor in Claim 5, e is 0, 1, 2 or 3,

   f is 0, 1 or 2

   and the sum of e+f is ≤3,

   with the proviso that the organopolysiloxanes comprise at least 2 hydrogen atoms bonded to Si.
8. Silicone compositions that can be crosslinked according to any of Claims 1 to 7, characterized in that the organosilicon compounds (B) used are organopolysiloxanes of the formula
   
           H_xR_3-xSiO(SiR₂O)_y(SiRHO)_zSiR_3-xH_x     (VII),
   
   wherein

   R has the definition specified therefor in Claim 5,

   x is 0, 1 or 2,

   y is 0 or an integer from 1 to 1500 and

   z is 0 or an integer from 1 to 200,

   with the proviso that the organopolysiloxanes of the formula (VII) comprise at least 2 hydrogen atoms bonded to Si.
9. Silicone compositions that can be crosslinked according to any of Claims 1 to 8, characterized in that the platinum catalysts (D) used are cyclopentadienyl complexes of platinum of the formula (XI)

   

   wherein

   Z is a hydrogen atom or a linear or branched aliphatic hydrocarbon radical or a radical of the formula
   
           - (CR'₂)_g-SiR⁴ _oR⁵ _pR⁹ _q,
   
   wherein

   g is an integer from 1 to 8,

   o is 0, 1 or 2,

   p is 0, 1, 2 or 3 and

   q is 0, 1, 2 or 3

   with the proviso that the sum of (o+p+q) is ≤3,

   R' is the same or different and is a hydrogen atom or a monovalent, unsubstituted or substituted hydrocarbon radical,

   R^2a is the same or different and is an alkyl, aryl, arylalkyl or alkylaryl radical, which may be interrupted by heteroatoms such as O, N, S or P, wherein the hydrogens may be substituted by halogen atoms or radicals of the formula -SiR² ₃, wherein

   R² is the same or different and is a monovalent, unsubstituted or substituted, linear, cyclic or branched hydrocarbon radical,

   R^2b is the same or different and is a hydrogen atom or a monovalent, unsubstituted or substituted, linear or branched, aliphatically saturated or unsaturated or aromatically unsaturated hydrocarbon radical, in which individual carbon atoms may be replaced by O, N, S or P atoms and which can form fused rings with the cyclopentadienyl radical, or one or more radicals R^2b can be a radical of the formula -SiR³ ₃, wherein

   R³ is the same or different and is a monovalent, unsubstituted or substituted, aliphatically saturated hydrocarbon radical, which may be interrupted by heteroatoms, or an aliphatically unsaturated, optionally substituted hydrocarbon radical or a siloxy radical bonded via oxygen,

   R⁴ is the same or different and is a hydrogen atom or a monovalent, unsubstituted or substituted, linear or branched, aliphatically saturated or unsaturated or aromatically unsaturated hydrocarbon radical, in which individual carbon atoms may be replaced by O, N, S or P atoms,

   R⁵ is the same or different and is a hydrolyzable functional group selected from the group of

   carboxyl -O-C(O)R⁶,

   oxime -O-N=CR⁶ ₂,

   alkoxy -OR⁶,

   alkenyloxy -O-R⁸

   amide -NR⁶-C(O)R⁷,

   amine -NR⁶R⁷,

   aminoxy -O-NR⁶R⁷,

   wherein

   R⁶ is the same or different and is an H atom or an alkyl, aryl, arylalkyl or alkylaryl radical,

   R⁷ is the same or different and is an alkyl, aryl, arylalkyl or alkylaryl radical,

   R⁸ is a linear or branched, aliphatically unsaturated organic radical,

   R⁹ is the same or different and is a monovalent linear, cyclic or branched, oligomeric or polymeric organosilicon radical, which may comprise one or more groups selected from

   a) aliphatically saturated or unsaturated groups having 1 to 30 carbon atoms, in which individual carbon atoms may be replaced by halogen, O, N, S or P atoms,

   b) aromatic groups having 1 to 30 carbon atoms, in which individual carbon atoms may be replaced by halogen, O, N, S or P atoms,

   c) hydrogen atoms bonded to Si

   d) hydroxyl groups and

   e) hydrolyzable groups.
10. Silicone compositions that can be crosslinked according to any of Claims 1 to 9, characterized in that the (methylcyclopentadienyl)trimethylplatinum complex is used as platinum catalyst (D).
11. Method for preparing the silicone compositions that can be crosslinked according to any of Claims 1 to 10, characterized in that

    (A) organosilicon compounds comprising Si-C-bonded radicals having aliphatic carbon-carbon multiple bonds,

    (B) organosilicon compounds comprising hydrogen atoms bonded to Si
    or instead of (A) and (B)

    (C) organosilicon compounds comprising Si-C-bonded radicals having aliphatic carbon-carbon multiple bonds and hydrogen atoms bonded to Si,

    (D) platinum catalysts that can be activated by light of wavelength 200 to 500 nm, preferably UV light of wavelength 200 to 400 nm, selected from the group of cyclopentadienyl complexes of platinum and

    (E) organophosphorus compounds selected from the group of the formulae (I), (II) and (III)
    are mixed with one another.
12. Use of the crosslinkable compositions according to any of Claims 1 to 10 for producing moldings, casting materials, adhesives or coatings.
13. Method for crosslinking the silicone compositions according to any of Claims 1 to 10 by irradiation with light, preferably UV light, wherein the organophosphorus compounds (E) in this case lose their inhibiting effect by deactivation and the silicone compositions crosslink.